/* * ng_tty.c * * Copyright (c) 1996-1999 Whistle Communications, Inc. * All rights reserved. * * Subject to the following obligations and disclaimer of warranty, use and * redistribution of this software, in source or object code forms, with or * without modifications are expressly permitted by Whistle Communications; * provided, however, that: * 1. Any and all reproductions of the source or object code must include the * copyright notice above and the following disclaimer of warranties; and * 2. No rights are granted, in any manner or form, to use Whistle * Communications, Inc. trademarks, including the mark "WHISTLE * COMMUNICATIONS" on advertising, endorsements, or otherwise except as * such appears in the above copyright notice or in the software. * * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * Author: Archie Cobbs * * $FreeBSD$ * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $ */ /* * This file implements a terminal line discipline that is also a * netgraph node. Installing this line discipline on a terminal device * instantiates a new netgraph node of this type, which allows access * to the device via the "hook" hook of the node. * * Once the line discipline is installed, you can find out the name * of the corresponding netgraph node via a NGIOCGINFO ioctl(). * * Incoming characters are delievered to the hook one at a time, each * in its own mbuf. You may optionally define a ``hotchar,'' which causes * incoming characters to be buffered up until either the hotchar is * seen or the mbuf is full (MHLEN bytes). Then all buffered characters * are immediately delivered. * * NOTE: This node operates at spltty(). */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include NET_NEEDS_GIANT("ng_tty"); /* Misc defs */ #define MAX_MBUFQ 3 /* Max number of queued mbufs */ #define NGT_HIWATER 400 /* High water mark on output */ /* Per-node private info */ struct ngt_sc { struct tty *tp; /* Terminal device */ node_p node; /* Netgraph node */ hook_p hook; /* Netgraph hook */ struct mbuf *m; /* Incoming data buffer */ struct mbuf *qhead, **qtail; /* Queue of outgoing mbuf's */ short qlen; /* Length of queue */ short hotchar; /* Hotchar, or -1 if none */ u_int flags; /* Flags */ struct callout_handle chand; /* See man timeout(9) */ }; typedef struct ngt_sc *sc_p; /* Flags */ #define FLG_TIMEOUT 0x0001 /* A timeout is pending */ #define FLG_DEBUG 0x0002 /* Debugging */ #ifdef INVARIANTS #define QUEUECHECK(sc) \ do { \ struct mbuf **mp; \ int k; \ \ for (k = 0, mp = &sc->qhead; \ k <= MAX_MBUFQ && *mp; \ k++, mp = &(*mp)->m_nextpkt); \ if (k != sc->qlen || k > MAX_MBUFQ || *mp || mp != sc->qtail) \ panic("%s: queue", __func__); \ } while (0) #else #define QUEUECHECK(sc) do {} while (0) #endif /* Line discipline methods */ static int ngt_open(struct cdev *dev, struct tty *tp); static int ngt_close(struct tty *tp, int flag); static int ngt_read(struct tty *tp, struct uio *uio, int flag); static int ngt_write(struct tty *tp, struct uio *uio, int flag); static int ngt_tioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct thread *); static int ngt_input(int c, struct tty *tp); static int ngt_start(struct tty *tp); /* Netgraph methods */ static ng_constructor_t ngt_constructor; static ng_rcvmsg_t ngt_rcvmsg; static ng_shutdown_t ngt_shutdown; static ng_newhook_t ngt_newhook; static ng_connect_t ngt_connect; static ng_rcvdata_t ngt_rcvdata; static ng_disconnect_t ngt_disconnect; static int ngt_mod_event(module_t mod, int event, void *data); /* Other stuff */ static void ngt_timeout(void *arg); #define ERROUT(x) do { error = (x); goto done; } while (0) /* Line discipline descriptor */ static struct linesw ngt_disc = { ngt_open, ngt_close, ngt_read, ngt_write, ngt_tioctl, ngt_input, ngt_start, ttymodem }; /* Netgraph node type descriptor */ static struct ng_type typestruct = { .version = NG_ABI_VERSION, .name = NG_TTY_NODE_TYPE, .mod_event = ngt_mod_event, .constructor = ngt_constructor, .rcvmsg = ngt_rcvmsg, .shutdown = ngt_shutdown, .newhook = ngt_newhook, .connect = ngt_connect, .rcvdata = ngt_rcvdata, .disconnect = ngt_disconnect, }; NETGRAPH_INIT(tty, &typestruct); /* * XXXRW: ngt_unit is protected by ng_tty_mtx. ngt_ldisc is constant once * ng_tty is initialized. ngt_nodeop_ok is untouched, and might want to be a * sleep lock in the future? */ static int ngt_unit; static int ngt_nodeop_ok; /* OK to create/remove node */ static int ngt_ldisc; static struct mtx ng_tty_mtx; MTX_SYSINIT(ng_tty, &ng_tty_mtx, "ng_tty", MTX_DEF); /****************************************************************** LINE DISCIPLINE METHODS ******************************************************************/ /* * Set our line discipline on the tty. * Called from device open routine or ttioctl() at >= splsofttty() */ static int ngt_open(struct cdev *dev, struct tty *tp) { struct thread *const td = curthread; /* XXX */ char name[sizeof(NG_TTY_NODE_TYPE) + 8]; sc_p sc; int s, error; /* Super-user only */ if ((error = suser(td))) return (error); s = splnet(); (void) spltty(); /* XXX is this necessary? */ tp->t_hotchar = NG_TTY_DFL_HOTCHAR; /* Initialize private struct */ MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO); if (sc == NULL) { error = ENOMEM; goto done; } sc->tp = tp; sc->hotchar = NG_TTY_DFL_HOTCHAR; sc->qtail = &sc->qhead; QUEUECHECK(sc); callout_handle_init(&sc->chand); /* Setup netgraph node */ ngt_nodeop_ok = 1; error = ng_make_node_common(&typestruct, &sc->node); ngt_nodeop_ok = 0; if (error) { FREE(sc, M_NETGRAPH); goto done; } mtx_lock(&ng_tty_mtx); snprintf(name, sizeof(name), "%s%d", typestruct.name, ngt_unit++); mtx_unlock(&ng_tty_mtx); /* Assign node its name */ if ((error = ng_name_node(sc->node, name))) { log(LOG_ERR, "%s: node name exists?\n", name); ngt_nodeop_ok = 1; NG_NODE_UNREF(sc->node); ngt_nodeop_ok = 0; goto done; } /* Set back pointers */ NG_NODE_SET_PRIVATE(sc->node, sc); tp->t_lsc = sc; /* * Pre-allocate cblocks to the an appropriate amount. * I'm not sure what is appropriate. */ ttyflush(tp, FREAD | FWRITE); clist_alloc_cblocks(&tp->t_canq, 0, 0); clist_alloc_cblocks(&tp->t_rawq, 0, 0); clist_alloc_cblocks(&tp->t_outq, MLEN + NGT_HIWATER, MLEN + NGT_HIWATER); done: /* Done */ splx(s); return (error); } /* * Line specific close routine, called from device close routine * and from ttioctl at >= splsofttty(). This causes the node to * be destroyed as well. */ static int ngt_close(struct tty *tp, int flag) { const sc_p sc = (sc_p) tp->t_lsc; int s; s = spltty(); ttyflush(tp, FREAD | FWRITE); clist_free_cblocks(&tp->t_outq); if (sc != NULL) { if (sc->flags & FLG_TIMEOUT) { untimeout(ngt_timeout, sc, sc->chand); sc->flags &= ~FLG_TIMEOUT; } ngt_nodeop_ok = 1; ng_rmnode_self(sc->node); ngt_nodeop_ok = 0; tp->t_lsc = NULL; } splx(s); return (0); } /* * Once the device has been turned into a node, we don't allow reading. */ static int ngt_read(struct tty *tp, struct uio *uio, int flag) { return (EIO); } /* * Once the device has been turned into a node, we don't allow writing. */ static int ngt_write(struct tty *tp, struct uio *uio, int flag) { return (EIO); } /* * We implement the NGIOCGINFO ioctl() defined in ng_message.h. */ static int ngt_tioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct thread *td) { const sc_p sc = (sc_p) tp->t_lsc; int s, error = 0; s = spltty(); switch (cmd) { case NGIOCGINFO: { struct nodeinfo *const ni = (struct nodeinfo *) data; const node_p node = sc->node; bzero(ni, sizeof(*ni)); if (NG_NODE_HAS_NAME(node)) strncpy(ni->name, NG_NODE_NAME(node), sizeof(ni->name) - 1); strncpy(ni->type, node->nd_type->name, sizeof(ni->type) - 1); ni->id = (u_int32_t) ng_node2ID(node); ni->hooks = NG_NODE_NUMHOOKS(node); break; } default: ERROUT(ENOIOCTL); } done: splx(s); return (error); } /* * Receive data coming from the device. We get one character at * a time, which is kindof silly. * Only guaranteed to be at splsofttty() or spltty(). */ static int ngt_input(int c, struct tty *tp) { const sc_p sc = (sc_p) tp->t_lsc; const node_p node = sc->node; struct mbuf *m; int s, error = 0; if (!sc || tp != sc->tp) return (0); s = spltty(); if (!sc->hook) ERROUT(0); /* Check for error conditions */ if ((tp->t_state & TS_CONNECTED) == 0) { if (sc->flags & FLG_DEBUG) log(LOG_DEBUG, "%s: no carrier\n", NG_NODE_NAME(node)); ERROUT(0); } if (c & TTY_ERRORMASK) { /* framing error or overrun on this char */ if (sc->flags & FLG_DEBUG) log(LOG_DEBUG, "%s: line error %x\n", NG_NODE_NAME(node), c & TTY_ERRORMASK); ERROUT(0); } c &= TTY_CHARMASK; /* Get a new header mbuf if we need one */ if (!(m = sc->m)) { MGETHDR(m, M_DONTWAIT, MT_DATA); if (!m) { if (sc->flags & FLG_DEBUG) log(LOG_ERR, "%s: can't get mbuf\n", NG_NODE_NAME(node)); ERROUT(ENOBUFS); } m->m_len = m->m_pkthdr.len = 0; m->m_pkthdr.rcvif = NULL; sc->m = m; } /* Add char to mbuf */ *mtod(m, u_char *) = c; m->m_data++; m->m_len++; m->m_pkthdr.len++; /* Ship off mbuf if it's time */ if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) { m->m_data = m->m_pktdat; NG_SEND_DATA_ONLY(error, sc->hook, m); sc->m = NULL; } done: splx(s); return (error); } /* * This is called when the device driver is ready for more output. * Called from tty system at splsofttty() or spltty(). * Also call from ngt_rcv_data() when a new mbuf is available for output. */ static int ngt_start(struct tty *tp) { const sc_p sc = (sc_p) tp->t_lsc; int s; s = spltty(); while (tp->t_outq.c_cc < NGT_HIWATER) { /* XXX 2.2 specific ? */ struct mbuf *m = sc->qhead; /* Remove first mbuf from queue */ if (!m) break; if ((sc->qhead = m->m_nextpkt) == NULL) sc->qtail = &sc->qhead; sc->qlen--; QUEUECHECK(sc); /* Send as much of it as possible */ while (m) { int sent; sent = m->m_len - b_to_q(mtod(m, u_char *), m->m_len, &tp->t_outq); m->m_data += sent; m->m_len -= sent; if (m->m_len > 0) break; /* device can't take no more */ m = m_free(m); } /* Put remainder of mbuf chain (if any) back on queue */ if (m) { m->m_nextpkt = sc->qhead; sc->qhead = m; if (sc->qtail == &sc->qhead) sc->qtail = &m->m_nextpkt; sc->qlen++; QUEUECHECK(sc); break; } } /* Call output process whether or not there is any output. We are * being called in lieu of ttstart and must do what it would. */ if (tp->t_oproc != NULL) (*tp->t_oproc) (tp); /* This timeout is needed for operation on a pseudo-tty, because the * pty code doesn't call pppstart after it has drained the t_outq. */ if (sc->qhead && (sc->flags & FLG_TIMEOUT) == 0) { sc->chand = timeout(ngt_timeout, sc, 1); sc->flags |= FLG_TIMEOUT; } splx(s); return (0); } /* * We still have data to output to the device, so try sending more. */ static void ngt_timeout(void *arg) { const sc_p sc = (sc_p) arg; int s; s = spltty(); sc->flags &= ~FLG_TIMEOUT; ngt_start(sc->tp); splx(s); } /****************************************************************** NETGRAPH NODE METHODS ******************************************************************/ /* * Initialize a new node of this type. * * We only allow nodes to be created as a result of setting * the line discipline on a tty, so always return an error if not. */ static int ngt_constructor(node_p node) { return (EOPNOTSUPP); } /* * Add a new hook. There can only be one. */ static int ngt_newhook(node_p node, hook_p hook, const char *name) { const sc_p sc = NG_NODE_PRIVATE(node); int s, error = 0; if (strcmp(name, NG_TTY_HOOK)) return (EINVAL); s = spltty(); if (sc->hook) ERROUT(EISCONN); sc->hook = hook; done: splx(s); return (error); } /* * Set the hooks into queueing mode (for outgoing packets) * Force single client at a time. */ static int ngt_connect(hook_p hook) { /*NG_HOOK_FORCE_WRITER(hook); NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));*/ return (0); } /* * Disconnect the hook */ static int ngt_disconnect(hook_p hook) { const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); int s; s = spltty(); if (hook != sc->hook) panic(__func__); sc->hook = NULL; m_freem(sc->m); sc->m = NULL; splx(s); return (0); } /* * Remove this node. The does the netgraph portion of the shutdown. * This should only be called indirectly from ngt_close(). */ static int ngt_shutdown(node_p node) { const sc_p sc = NG_NODE_PRIVATE(node); if (!ngt_nodeop_ok) return (EOPNOTSUPP); NG_NODE_SET_PRIVATE(node, NULL); NG_NODE_UNREF(sc->node); m_freem(sc->qhead); m_freem(sc->m); bzero(sc, sizeof(*sc)); FREE(sc, M_NETGRAPH); return (0); } /* * Receive incoming data from netgraph system. Put it on our * output queue and start output if necessary. */ static int ngt_rcvdata(hook_p hook, item_p item) { const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); int s, error = 0; struct mbuf *m; if (hook != sc->hook) panic(__func__); NGI_GET_M(item, m); NG_FREE_ITEM(item); s = spltty(); if (sc->qlen >= MAX_MBUFQ) ERROUT(ENOBUFS); m->m_nextpkt = NULL; *sc->qtail = m; sc->qtail = &m->m_nextpkt; sc->qlen++; QUEUECHECK(sc); m = NULL; if (sc->qlen == 1) ngt_start(sc->tp); done: splx(s); if (m) m_freem(m); return (error); } /* * Receive control message */ static int ngt_rcvmsg(node_p node, item_p item, hook_p lasthook) { const sc_p sc = NG_NODE_PRIVATE(node); struct ng_mesg *resp = NULL; int error = 0; struct ng_mesg *msg; NGI_GET_MSG(item, msg); switch (msg->header.typecookie) { case NGM_TTY_COOKIE: switch (msg->header.cmd) { case NGM_TTY_SET_HOTCHAR: { int hotchar; if (msg->header.arglen != sizeof(int)) ERROUT(EINVAL); hotchar = *((int *) msg->data); if (hotchar != (u_char) hotchar && hotchar != -1) ERROUT(EINVAL); sc->hotchar = hotchar; /* race condition is OK */ break; } case NGM_TTY_GET_HOTCHAR: NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT); if (!resp) ERROUT(ENOMEM); /* Race condition here is OK */ *((int *) resp->data) = sc->hotchar; break; default: ERROUT(EINVAL); } break; default: ERROUT(EINVAL); } done: NG_RESPOND_MSG(error, node, item, resp); NG_FREE_MSG(msg); return (error); } /****************************************************************** INITIALIZATION ******************************************************************/ /* * Handle loading and unloading for this node type */ static int ngt_mod_event(module_t mod, int event, void *data) { /* struct ng_type *const type = data;*/ int s, error = 0; switch (event) { case MOD_LOAD: /* Register line discipline */ s = spltty(); if ((ngt_ldisc = ldisc_register(NETGRAPHDISC, &ngt_disc)) < 0) { splx(s); log(LOG_ERR, "%s: can't register line discipline", __func__); return (EIO); } splx(s); break; case MOD_UNLOAD: /* Unregister line discipline */ s = spltty(); ldisc_deregister(ngt_ldisc); splx(s); break; default: error = EOPNOTSUPP; break; } return (error); }